Attached duct propeller system

ABSTRACT

An attached duct propeller system may include at least one propeller blade having at least one blade tip. A duct having an inner wall may surround the at least one propeller blade. The at least one propeller blade may attach to the inner wall of the duct. In certain embodiments, the attached duct propeller system may include a propeller shaft attached to a bore of the at least one propeller blade. In certain embodiments, the at least one blade tip may be trimmed to allow alignment within the duct and allow for the attachment of the at least one blade to the inner wall of the duct. The attached duct propeller system may be used for vehicles that use at least one propeller for propulsion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application Ser. No. 61/738,584, filed Dec. 18, 2012, the contents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to propellers and, more particularly, to a propeller duct attached to at least one propeller blade tip of at least one propeller blade of a propeller.

Standard marine propellers without a duct do not contain and focus thrusted water and thereby lose thrust energy that is spun outward with the rotation of the propeller. By allowing the water to dissipate outward from the at least one propeller blade, the propeller loses efficiency.

Standard marine propellers that do not have attached ducts are inefficient and lose thrust energy by spinning thrusted water outward from the blade tips of the propeller.

As can be seen, there is a need for a attached duct propeller system that prevents thrusted water from being spun outward away from the centerline of thrust.

SUMMARY OF THE INVENTION

In one aspect of the present invention, an attached duct propeller system comprises: at least one propeller blade having at least one blade tip; and a duct having an inner wall, wherein the duct surrounds the at least one propeller blade, wherein the at least one propeller blade attaches to the inner wall of the duct.

In another aspect of the present invention, an attached duct propeller system comprises: at least one propeller blade having at least one blade tip, wherein the at least one blade tip is trimmed; and a duct having an inner wall, wherein the duct surrounds the at least one propeller blade, wherein the at least one propeller blade attaches to the inner wall of the duct.

In another aspect of the present invention, a method of improving efficiency in a propelled device, comprises: providing a propeller having at least one propeller blade; providing a substantially cylindrical duct having a duct inside diameter; removing a portion of at least one tip of the at least one propeller blade so that the propeller fits snugly inside the duct; attaching the at least one blade to the duct; and balancing the propeller.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary embodiment of the present invention;

FIG. 2 is an exploded perspective view of an exemplary embodiment of the present invention;

FIG. 3 is a section view of an exemplary embodiment of the present invention taken along line 3-3 in FIG. 2;

FIG. 4 is a section view of an exemplary embodiment of the present invention taken along line 4-4 in FIG. 3;

FIG. 5 is a perspective view of an alternate embodiment of the present invention;

FIG. 6 is an exploded perspective view of an alternate embodiment of the present invention;

FIG. 7 is a section view of an alternate embodiment of the present invention taken along line 7-7 in FIG. 6; and

FIG. 8 is a section view of an alternate embodiment of the present invention taken along line 8-8 in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

Broadly, an embodiment of the present invention provides an attached duct propeller system that may include at least one propeller blade having at least one blade tip. A duct having an inner wall may surround the at least one propeller blade. The at least one propeller blade may attach to the inner wall of the duct. In certain embodiments, the attached duct propeller system may include a propeller shaft attached to a bore of the at least one propeller blade. In certain embodiments, the at least one blade tip may be trimmed to allow alignment within the duct and allow for the attachment of the at least one blade to the inner wall of the duct. The attached duct propeller system may be used for vehicles that use at least one propeller for propulsion.

The present invention may improve thrust and efficiency, which may also reduce fuel usage. The present invention may have a duct surrounding at least one blade that may prevent thrusted water from being spun outward away from the centerline of thrust. A marine vessel or the like that is so equipped may go faster at the same rpm versus an ordinary propeller since water, or any other liquid, may be focused into a tight column, thereby increasing thrust and efficiency.

As is illustrated in FIGS. 1 through 8, the present invention may include at least one propeller blade 10. The at least one propeller blade 10 may attach to a propeller shaft 20. The at least one propeller blade 10 may have a center bore 24. The center bore 24 may have a plurality of splines 26. The propeller shaft 20 may be a splined propeller shaft 20 so that the splines 26 along the center bore 24 may line up with the splined propeller shaft 20. The propeller shaft 20 may be attached to an engine/transmission 18. The engine/transmission 18 may be attached to a boat or the like. A duct 12 may surround the at least one propeller blade 10. The duct 12 may have an outer wall 16 and an inner wall 14. At least one propeller blade tip 22 may be trimmed so that the at least one propeller blade 10 may fit within the inner wall 14 of the duct 12. The trimmed end of the at least one propeller blade tip 22 may be a flat surface parallel to the centerline of thrust. The at least one propeller blade 10 and the duct 12 may be secured to the propeller shaft 20. A nut 28 and washer 30, or the like, may be used in order to secure the duct 12 and at least one propeller blade 10 to the propeller shaft 20.

A standard marine propeller spins and forces water rearward, but a percentage of the thrust is spun ‘out’ or ‘away’ from the tips of the propellers instead of being directed rearward to propel the vessel. By encasing the propeller in its own attached duct, thrust water may not escape outward and may be forced and focused to travel through the duct. This narrowing of the fluid trajectory increases the amount of water that may be converted for thrust for the very same revolutions per minute (rpm). Since more water may be directed for thrust, a vessel so equipped may travel faster for the same rpm. This may also translate to lower fuel consumption and greater efficiency. The attached duct may also stiffen the propeller blades, thereby reducing flex. Since the propeller blades may not flex, they thrust a greater volume of water, which also increases thrust and efficiency.

A method of making the present invention may include the following. In certain embodiments the diameter of a marine propeller blade 10 may be measured, such as approximately 14.25 inches. In this particular embodiment, an approximately ⅛ inch thick substantially cylindrical duct 12, approximately 8 inches high may be manufactured with an inside diameter equal to approximately ¾ inches less than the diameter of the selected marine propeller such as 13.5 inches. The remaining approximately 0.375 inches of the each propeller blade tip 22 may be removed, leaving a flat surface parallel to the centerline of thrust. This may also leave the total diameter of the propeller blades and duct the same as the original propeller blades by itself. The substantially cylindrical duct 12 may then be placed around the shortened propeller blades 10, approximately 3 inches from a hub. Each blade tip may be welded to the inside of the substantially cylindrical duct 12. The completed assembly may then be balanced and painted. In certain embodiments, thicker propeller blades may require less trimming in order to produce a sufficient flat surface for the welding of the duct. In certain embodiments, the attached duct propeller system may be made from scratch as well, and in this situation, welding may not be required as the molding or machining process may fabricate a complete attached-duct propeller as one solid piece of metal.

In larger applications such as tanker ships, container ships, passenger ships, naval and coast guard ships, and the like, the substantially cylindrical duct may also be fabricated in sequential sections and attached by welding, riveting or the like, in increments until a fully enclosed duct may be completed.

In certain embodiments, the height of the substantially cylindrical duct 12 and distance from the hub may be changed to accommodate a variety of engine configurations. In certain embodiments, similar substantially cylindrical duct 12 may be fabricated and attached to standard aviation propellers to increase thrust and efficiency.

A method of using the present invention may include the following. Replacing a standard marine propeller with an attached duct propeller system, a boat may accelerate faster and have a higher top speed. The boat may use less fuel and go farther per tank. The attached duct propeller system may reduce pollution and greenhouse gases. In military applications, naval and coast guard ships may perform better and be more fuel efficient, saving millions of gallons of fuel. In commercial applications, tanker ships, container ships, tug boats, cruise ships, and the like may use far less fuel. The existing propeller may be modified with no changes necessary to the vessel or aircraft superstructure.

In certain embodiments, the attached duct propeller system may be applied to aircrafts 32. At least one aircraft propeller blade 34 fitted with an attached substantially cylindrical duct 12 may also benefit from increased thrust, increased efficiency, and reduced fuel usage. A center bore 40 of the at least one aircraft propeller blade 34 may attach to the aircraft propeller shaft 36. The aircraft propeller shaft 36 may attach to the aircraft engine 38 so that the aircraft engine 38 may power the rotation of the at least one aircraft propeller blade 34. By forcing the thrusted air through the substantially cylindrical duct 12, a higher efficiency may be achieved over a standard aircraft propeller. By encasing the propeller in its own attached duct 12, thrust water may not escape outward and may be forced and focused to travel through the duct. This narrowing of the air trajectory increases the amount of air that may be converted for thrust for the very same revolutions per minute (rpm). Since more air may be directed for thrust, a vessel so equipped may travel faster for the same rpm. This may also translate to lower fuel consumption and greater efficiency.

Although the present embodiment of the invention may be illustrated installed on a typical small boat engine, it should be noted that the invention may be configured and installed on any type of vehicle that uses at least one propeller for propulsion including but not limited to ships, small watercrafts and aircraft as known by those in the art.

It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. 

What is claimed is:
 1. An attached duct propeller system comprising: at least one propeller blade having at least one blade tip; and a duct having an inner wall, wherein the duct surrounds the at least one propeller blade, wherein the at least one propeller blade attaches to the inner wall of the duct.
 2. The attached duct propeller system of claim 1, wherein the at least one propeller blade is welded to the inner wall of the duct.
 3. The attached duct propeller system of claim 1, further comprising a propeller shaft, wherein a center bore of the at least one propeller blade attaches to the propeller shaft.
 4. The attached duct propeller system of claim 3, further comprising an engine/transmission attached to the propeller shaft.
 5. An attached duct propeller system comprising: at least one propeller blade having at least one blade tip, wherein the at least one blade tip is trimmed; and a duct having an inner wall, wherein the duct surrounds the at least one propeller blade, wherein the at least one propeller blade attaches to the inner wall of the duct.
 6. The attached duct propeller system of claim 5, wherein the at least one blade tip is trimmed to a flat surface parallel to a centerline of thrust.
 7. The attached duct propeller system of claim 5, wherein the at least one propeller blade is welded to the inner wall of the duct.
 8. The attached duct propeller system of claim 5, further comprising a propeller shaft, wherein a center bore of the at least one propeller blade attaches to the propeller shaft.
 9. The attached duct propeller system of claim 8, further comprising an engine/transmission attached to the propeller shaft.
 10. A method of improving efficiency in a propelled device, comprising: providing a propeller having at least one propeller blade; providing a substantially cylindrical duct having a duct inside diameter; removing a portion of at least one tip of the at least one propeller blade so that the propeller fits snugly inside the duct; attaching the at least one blade to the duct; and balancing the propeller.
 11. The method of claim 10, further comprising the step of rotating the propeller to provide an impulse reaction to propel a vehicle that uses at least one propeller for propulsion.
 12. The method of claim 10 further comprising the step of attaching a shaft of the at least one propeller blade to an engine/transmission. 